Pharmacology: Common Drug Reactions and Terminologies

Anaphylactic Reaction and Drug Effects

• Anaphylactic reaction is a severe allergic reaction that occurs immediately after drug administration.
• Drug tolerance refers to a decreased physiologic response to repeated administration of a drug or chemically related substance.
• Cumulative effect is the increasing response to repeated doses of a drug.
• Idiosyncratic effect is an unexpected peculiar response to a drug.
• Drug abuse is the inappropriate intake of a substance, either continually or periodically.
• Drug dependence is a person's reliance or need to take a drug or substance.
• Addiction is caused by biochemical changes in body tissues, especially the nervous system.
• Habituation is emotional reliance on a drug to maintain a sense of well-being.

Drug Interactions

• Drug interaction occurs when the effects of one drug are modified by the prior or concurrent administration of another drug.
• Drug antagonism is when the conjoint effect of two drugs is less than the effect of each drug acting separately.
• Summation is when the combined effect of two drugs equals the sum of the individual effects of each agent.
• Synergism is when the combined effects of drugs are greater than the sum of each individual agent acting independently.
• Potentiation is when the concurrent administration of two drugs increases the effect of one drug.

Therapeutic Actions of Drugs

• Palliative actions relieve the symptoms of a disease but do not affect the disease itself.
• Curative actions treat a disease or condition.
• Supportive actions sustain body functions until other treatments or the body's response can take over.
• Substitutive actions replace body fluids or substances.
• Chemotherapeutic actions destroy malignant cells.
• Restorative actions return the body's health.

Pharmacokinetics

• Pharmacokinetics refers to what the body does to drugs and encompasses all issues of drug interactions and drug clearance metabolism.
• Absorption is the process by which a drug passes from its site of administration into the bloodstream.
• Factors that affect drug absorption include blood flow, pain, stress, foods, exercise, nature of the absorbing surface, solubility of the drug, and pH.
• IM injection sites commonly used are the deltoid, dorsogluteal, rectus femoris, vastus lateralis, and ventrogluteal muscles.
• Types of muscle include striated muscle (skeletal muscle), smooth muscle (internal organs), and cardiac muscle.

Intravenous Route

• The intravenous route is the most rapid route of absorption of medications.
• Isotonic solutions are IV fluids that have a similar concentration of dissolved particles as blood.
• Complications of IV infusion include infiltration, which occurs when the needle is out of the vein.
• Signs of infiltration include pain, swelling, skin is cold at the needle site, pallor of the site, and a decrease or stop in the flow of IV rate.
• Nursing interventions for infiltration include changing the site of the needle.